INVIZITRAK FAQ

General↓

What is InviziTrak?↓

InviziTrak is a hardware system that makes green screen tracking markers invisible by recording them separately from the main footage. In post-production, this gives you two pieces of footage for each shot: one with tracking markers for match-moving and one without for completely clean keying.

How does InviziTrak work?↓

Footage is usually shot with a shutter angle of 180 degrees, which means the shutter is only open for half a frame period. We use this extra time period to capture a second set of frames with laser projected tracking markers. Your footage still looks exactly the same: same motion, same exposure, same ISO, same speed.

How do I use InviziTrak? ↓

Before shooting, just attach the wireless sync box to the camera, set to 48fps and 360 degree shutter angle, plug in the tracking marker projector, and you are ready to shoot.

Is InviziTrak safe?↓

Absolutely. InviziTrak adheres to OSHA guidelines, is FDA compliant, and is safe to use on set, near actors and crew.

Is InviziTrak distracting to users?↓

Laser markers are not distracting to cast and crew as they are dimmable and projected behind the talent. Camera sensors are highly sensitive to the color green, so when properly exposed, the InviziTrak markers are actually quite dim to the eye while showing up clearly on camera.

Where does InviziTrak project the laser markers?↓

Markers can be projected on green/blue screens or on any surface you might need a camera track on (i.e. a wall or flooring). InviziTrak can also be used on black velvet, dark surfaces and even sand or snow.

Cameras/Frame Rates↓

What cameras does InviziTrak work with?↓

ARRI, Sony, RED and Vision Research Phantom.

What frame rate do I have to shoot at? ↓

Twice your final frame rate. For example, for a project shooting with 24fps (and 180 degree standard shutter), cameras must be set to shoot 48fps / 360 degree shutter to produce InviziTrak compatible footage. In post production, this footage is then split to become two streams of 24fps / 180 degree shutter, one with markers, and one without.

What frame rates does InviziTrak support?↓

InviziTrak can be used at any industry standard frame rate: 24, 23.98, 25, 30, 50, 60 and off-speed rates from 1-120fps. Please note, your digital cinema camera will need to be able to run at 2x your projection frame rate.

Does InviziTrak work with slow-motion? ↓

Yes. It actually works at any frame rate 1-120fps. Frame rates beyond 120fps will be tested soon, but we anticipate InviziTrak will work up to 500fps. Remember when shooting slow-motion, you still need to shoot double your final frame rate. For example, if you want your shot to be at 75fps you'll need to film it at 150fps, resulting in two clips at 75fps.

Synching↓

How does InviziTrak sync with my camera? ↓

The InviziTrak Transmitter, which mounts to your camera, can read your camera's shutter timing from any of the following: HD-SDI, RED CTRL port, ARRI RS, Phantom F-Sync, Genlock.

Does InviziTrak work with multiple cameras? ↓

Yes, but the cameras will need to be genlocked together. A single InviziTrak Transmitter is required on one camera.

Controls↓

How do I control InviziTrak?↓

The included iPad allows you to wirelessly activate different laser patterns, set laser exposure, and swap between monitoring video with tracking markers visible or marker-less clean output on your 24fps monitor.

Are the lasers adjustable?↓

Yes. Each tracking marker projector can control six wirelessly dimmable laser modules. Each laser module is mounted on a ball-head and can be fitted with different optics to generate dense grids, sparse grids, dots or crosshairs to suit the environment. The brightness of the lasers is similar to that found on green laser pointers; bright enough for most lighting conditions, but not so powerful as to be hazardous.

How do I control multiple Projectors? ↓

Simple. Multiple projectors can be synchronized to the same transmitter resulting in all lasers being controlled on a single iPad.

Does InviziTrak support DMX control? ↓

Not yet, but we're considering this. Drop us a line on our Contact page and let us know if this interests you.

Post Workflow↓

What compositing software is InviziTrak compatible with?↓

Any software. Nuke, Flame, After Effects, Fusion, Smoke, etc.

Does using InviziTrak change my footage?↓

No. There is no loss in quality, motion blur, or light exposure.

What is the post production workflow for InviziTrak?↓

In post production, the clean markerless frames are split off into a separate stream, and keyed. Meanwhile, the frames with markers are used for matchmoving.

Do you have a plug-in for splitting the footage up?↓

Not at this time, but this can be accomplished in any VFX or editing software by making two copies of a RAW plate: one trimmed to the first marker frame and another trimmed to the first clean frame. Then both clips are sped up to 200% speed (with no frame-blending).

Features↓

What is the Transmitter for? ↓

The sync Transmitter mounts on your camera and extracts the shutter timing from HD-SDI, ARRI RS, Red CRTL or Genlock from the camera and wirelessly synchronizes the tracking Marker Projector with the shutter. This enables InviziTrak to only project its laser markers during the marker frames and keeps your clean frames clear of any markers.

What does the Projector do?↓

It mounts to your lighting grid or a light stand and projects the tracking markers using aimable lasers.

What mounting & power does the Projector have?↓

InviziTrak mounts include Junior/Baby pin for stands, 100x100 VESA for monitor mounts, and Omega twist-lock clamps for overhead lighting grids. For power, InviziTrak has an AC input and an Anton Bauer battery mount.

Can I use InviziTrak on very jerky shots, like chaotic hand-held?↓

For jerky shots, InviziTrak allows you to activate “constant-on” tracking markers which remain lit in both sets of frames. These can be used to “jitter reduce” the track, and improve the match-move while still greatly reducing the number of tracking markers that need to be removed versus traditional markers. An additional, the benefit of InviziTrak is that the duration of the laser pulse can be as short as 1 millisecond, which greatly reduces the amount of motion blur on the tracking marker on fast camera movements.

Does InviziTrak have a backup system?↓

Even in the most extreme movement scenarios, the set of frames with markers present is your backup: it can always be used just like traditional footage, for both keying and tracking. So there’s always a usable plate being captured, no matter what. Furthermore, the clean frames can help with any paint work by providing marker-less reference frames to the sample frame.

What shape of markers does InviziTrak offer?↓

Grid, cross & dot markers.

Does it run on battery or wall power? ↓

Both.

VFX Benefits & Environments↓

What kind of tracking does InviziTrak work for?↓

InviziTrak is perfect for not just green/blue screens but also match-moving CG assets into environments that lack natural tracking features such as sand, night exteriors, walls or other textureless surfaces.

Does InviziTrak work for reflective environments?↓

Since InviziTrak’s markers never need to be painted out, they are perfect for use in reflective environments like modern glass buildings, cars, shiny floors, chrome and refractive product shoots where markers are often reflected numerous times.

What about bright environments?↓

InviziTrak's high brightness lasers are viewable in high-brightness environments. All InviziTrak lasers are compliant with FDA and IEC safety standards.

How does it work with defocused backgrounds?↓

InviziTrak offers removable Cross Lens Adapters, which produce “+” shaped markers that stay sharp when the surface is out of focus.

How big of a green screen can I use?↓

One InviziTrak unit can project on an 80' cyc. For larger green screens, the Transmitter can synchronize multiple projectors within its radio’s range, typically a few hundred meters and allow Projectors to automatically synchronize with each other.

Does InviziTrak eliminate motion blur?↓

InviziTrak is capable of projecting with such short laser on-times (1ms) that motion-blur can be effectively eliminated, making tracking during fast pans a breeze.

Does it work on fast camera motion?↓

InviziTrak takes advantage of two sets of frames, one frame where movement is sampled and an adjacent “clean” marker-less frame that is keyed. Sometimes during fast/jerky camera movements, such as chaotic hand-held, the track can theoretically slip due to interpolation. To prevent this, InviziTrak features a “constant on" mode to allow some lasers to remain active for all frames. This provides a reference to perform a "jitter reduction" camera track and produce a solid match-move, even during fast camera movements.

How does it work for complex match moves?↓

For the most complex 3D match moves InviziTrak offers the ability to project hundreds of markers, which accelerates tracking and makes for robust camera path reconstruction, but without polluting plates with more markers to roto out. Since you have two pieces of footage, you get the best of both worlds.

Is InviziTrak bright enough to use outside?↓

Yes, as long as your green/blue screen is not in direct sun. The 9 laser cubes have the brightest lasers, so we recommend using these for bright environments. We also suggest you always test before you shoot to make sure lasers are showing up bright enough on your green/blue screen.

Example Use Cases↓

General Green/Blue Screen↓

Any time you have actors on a green screen, they’re bound to cross over markers. The more camera movement, the more markers you need. The more actors, the more they cross. And roto costs keep going up. With InviziTrak these roto costs become zero. And you save time setting up and moving markers on set!

Hair and Foliage↓

Say you have someone with long blond hair over green-screen with a wind machine, and some branches out-of-focus. And it's a big moving shot, so you need a lot of markers. Well, every time they go behind the hair, or out out-of-focus branches, roto costs, that would normally be through the roof, are now zero.

Shiny Sets↓

Say you've got actors in a set with a shiny floor and beautiful reflections of your case… but unfortunately double the marker removal if you're using traditional markers. Except with InviziTrak, you've got totally clean backgrounds and floors.

Glass Sets↓

Say you're shooting a character looking out big glass windows, and it's a night scene too, so you're getting beautiful reflections of their face. And it's a big moving crane shot… well, all your markers are going to pass behind that beautiful reflection. Paint costs would be huge. Except with InviziTrak your artists can focus on the creative side of things.

CG Tracking I↓

Say you have an actor on a sand dune, and it's at night, and you need a CG robot walking around with them. Well, you're gonna need rock-solid camera tracks and a bunch of markers. So you burn up time and money putting little LEDs all over your set… making a bunch of footsteps in the dune that have to get painted out… wait, you could just use InviziTrak and you'd have totally clean footage and no wasted time on set putting out all those markers.

CG Tracking II↓

Say you need a CG creature climbing along the walls of a house. But they're white. And it's a complicated steadicam shot. Put up markers all over the wall, only to get painted out again? Nope - just turn on InviziTrak.